Dahlia Dahlia 'John Hill' (D)

Water

Dahlias require consistent moisture, so you should aim to water the Dahlia 'John Hill' deeply at least 2 to 3 times per week, depending on the weather conditions. Use a soaker hose or drip irrigation to deliver water directly to the base of the plant, avoiding wetting the foliage to minimize the risk of fungal infections. During the peak growing season, a dahlia may need around 1 to 2 gallons of water per week, but be sure to adjust this amount depending on rainfall and temperature. The soil should feel moist but not soggy at a depth of 1 inch. In particularly hot spells, increase the frequency to maintain the soil moisture levels.

Light

Dahlias thrive in full sun conditions, so the Dahlia 'John Hill' should be planted in a location that receives at least 6 to 8 hours of direct sunlight each day. Position the plant where it has unobstructed access to sunlight, away from taller plants that might cast shade. A spot with morning sunlight and some protection from intense afternoon sun can be ideal in hotter climates to prevent heat stress.

Temperature

Dahlias prefer moderate temperatures and will grow most vigorously when daytime temperatures range between 60°F and 70°F. Dahlia 'John Hill' can tolerate temperatures up to 90°F but will start to suffer if the temperature rises above that. The plant should not be exposed to temperatures below 50°F, as dahlias are sensitive to cold and may be damaged by frost. The ideal temperature range for most dahlias is between 60°F and 75°F for optimal growth.

Pruning

Prune Dahlias to promote bushier growth, increased airflow, and more blooms. For the Dahlia 'John Hill,' deadhead spent flowers regularly to encourage continued blooming. Cut back the stems by about one-third in early summer to encourage side branching. After the first frost has killed the foliage, cut the plant back to 4-6 inches above the ground. The best time to prune is during the active growing season and after the plant has finished blooming for the year.

Cleaning

As needed

Soil

The best soil mix for Dahlias is a well-draining, loamy soil with a pH between 6.5 and 7.0. Amend the soil with compost or peat moss to improve fertility and drainage. Add perlite or sand to loosen the soil if necessary, ensuring nutrients and water are accessible but excess moisture can drain away.

Repotting

Dahlias, including Dahlia 'John Hill', should be repotted every year. They are typically lifted from the ground after the first frost in the fall, stored during winter, and then replanted after the danger of frost has passed in the spring.

Humidity & Misting

Dahlias prefer moderate humidity levels. They thrive with humidity that mimics their native environments, so aiming for a range of 40-60% relative humidity is typically suitable for growing healthy plants.

Suitable locations

• Indoor

  Place in bright, indirect light; keep soil moist but well-drained.

• Outdoor

  Plant in well-drained soil; full sun after frost; frequent watering.

• Hardiness zone

  8-11 USDA

Life cycle

Dahlia 'John Hill' begins its life cycle when the tuber is planted in the ground after the last frost, given that it's a tender perennial susceptible to cold temperatures. The plant sprouts and a stem emerges, followed by leaves that photosynthesize to fuel growth. As it matures, the Dahlia 'John Hill' develops flower buds that eventually bloom into distinctive large flowers with a wide range of colors, depending on the variety. These blooms can occur from midsummer through fall, attracting pollinators. After flowering, if the blooms are left to wither, they can set seeds; however, Dahlias are more commonly propagated through division of their tubers. With the onset of winter, the top portion of the plant dies back while the tuber beneath the soil goes dormant, to be stored and replanted the following spring.

Propogation

• Propogation time

  Spring-Early Summer

• The optimum time for propagating Dahlia 'John Hill', commonly known as dahlia, is in the spring after the last frost when the soil has warmed to at least 60°F (15.6°C). The most popular method of propagation for dahlias is through division of the tubers, as these plants produce tuberous roots. To propagate by division, one should first carefully dig up the clump of dahlia tubers after the foliage has died back or in early spring. Then, using a sharp, clean knife, divide the clump into separate sections, making sure that each division has at least one eye, which is the point from where new growth will emerge. Divisions should be immediately replanted in well-draining soil at a depth of about 6 to 8 inches (15 to 20 centimeters), positioned so the eyes are facing upwards. Water the newly planted divisions thoroughly to help establish them. This method allows gardeners to rapidly expand their dahlia collections and maintain the specific characteristics of the 'John Hill' variety.